Morales Williams' 400m race will not count as an official world record due to a problem with the starting blocks, the United States Track and Field and Cross Country Coaches Association (USTFCCCA) announced on social media. The USTFCCCA described the performance of the young Canadian, who ran for the University of Georgia at a collegiate meet in Arkansas, as the "all-time world best", but it will not be ratified as a world record for the distance. 

The 19-year-old student won ahead of JeVaughn Powell (45.61) and Chris Robinson (45.62). The mark was initially accepted but the world record will remain at 44.52. This was set by American runner Michael Norman in March 2018. First, William Morales won his heat the day before with a time of 45.58, and the next day he beat his previous mark by more than a second. 

The starting blocks used in the race did not comply with World Athletics rules for ratification of world records, according to reports in the United States. The rules require the blocks to be linked to a World Athletics "start information system". This monitors reaction times. The USTFCCCA said in a statement that Morales Williams had undergone a post-competition drug test. "This was not an issue," AFP reported.

Despite this setback, the young athlete's talent is undeniable. He was the Canadian 400m champion in 2023 and began the indoor season with a time of 47.42, far from what he was capable of in Arkansas.

He was absent from last year's World Championships in Budapest. William Morales won his heat the day before with a time of 45.58. Morales Williams was a member of the Canadian U-20 team that won a bronze medal in the 4x400 m relay at Cali in 2022. He also won silver at the 2023 Pan Am Championships.